Disable AX TCs related to Table Header

The role for Table Header will be updated with
Blink CL, crrev.com/816423003.
After that CL is merged, these TCs will be enabled with new results.

BUG=435081

Review URL: https://codereview.chromium.org/823293003

Cr-Commit-Position: refs/heads/master@{#310011}
1 file changed